On Thu, 7 Nov 2013, Andreas Herrmann wrote: > And for sake of completeness. Here is some debug output with a kernel > that had your "slub: Handle NULL parameter in kmem_cache_flags" patch > applied. And of course there were a couple of unnamed slabs: > > ... > .bss : 0xc089fd80 - 0xc094cc4c ( 692 kB) > slub_debug_slabs (c2956a08): skbuff_fclone_cache, name (c06fc90c): > kmem_cache_node > slub_debug_slabs (c2956a08): skbuff_fclone_cache, name (c06fc91c): > kmem_cache > → slub_debug_slabs (c2956a08): skbuff_fclone_cache, name ( (null)): (null) > slub_debug_slabs (c2956a08): skbuff_fclone_cache, name ( (null)): (null) > slub_debug_slabs (c2956a08): skbuff_fclone_cache, name ( (null)): (null) > slub_debug_slabs (c2956a08): skbuff_fclone_cache, name ( (null)): (null) > slub_debug_slabs (c2956a08): skbuff_fclone_cache, name ( (null)): (null) > slub_debug_slabs (c2956a08): skbuff_fclone_cache, name ( (null)): (null) > slub_debug_slabs (c2956a08): skbuff_fclone_cache, name ( (null)): (null) > slub_debug_slabs (c2956a08): skbuff_fclone_cache, name ( (null)): (null) > slub_debug_slabs (c2956a08): skbuff_fclone_cache, name ( (null)): (null) > SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=4, Nodes=1 > ...
Well yes on bootstrap the slabs are initially created without a name. Later the name is provided. Before the introduction of the common kmalloc code the kmalloc caches had a generic name instead of NULL. I was not sure that this was a valid thing to do so I put NULL in there so that we can catch the uses.